This invention relates to fluid and vapor line systems which include fittings, and more particularly, to a fitting having an axially movable swaging ring.
For the automotive and other industries, fittings are commonly used to connect metal tubes and pipes to each other to provide a fluid or vapor connection.
One type of fittings often used is a ring having a conical bore for securing a male member formed at the end of a first tube inserted into a radially enlarged female body formed at the end of a second tube. For this type of fitting, the ring is loosely and slidably mounted on the first tube. The ring is mounted such that the enlarged diameter portion of the conical bore is directed toward the male member. To provide the fluid or vapor connection, the male member is first inserted into the female body. The ring is then slid along the first tube toward the female body and swaged over the female body with the male member inserted within. The swaging of the ring over the female body crushes the female body radially inward and creates a sealing surface between the female body and the male member. Once the ring is swaged over the female body, it retains the male member within the female body. The ring constantly applies a radially inward force to the female body. The female body reacts by applying a radially inward force to the male member. This radially inward force by the female body onto the male member prevents the male member from withdrawing from the female body, thus securing the male member within the female body. This type of fitting is prevalent in the art, and has proven effective in many fluid or vapor line applications.
Nevertheless, such fittings have occasionally been prone to failure. During insertion of the male member into the female body, the male member may not have been inserted sufficiently into the female body. Thus, when the ring is swaged over the female body, there is not sufficient surface between the crushed female body and the relational male member to form an effective sealing surface. Furthermore, if the male member has not been inserted sufficiently into the female body, upon swaging the ring over the female body the ring can bypass the portion of the female body overlaying the male member. Should such a situation occur, there is no radially inward force applied by the female body onto the male member, thus allowing the male member to be easily withdrawn from the female body.
While the swaging of the ring over the female body creates a sealing surface between the female body and the male member, the surface is still prone to leak should a gap develop between the female body and the male member.
One solution disclosed in prior art references is to apply a bonding agent onto the male member just prior to insertion of the male member into the female member. Examples of such bonding agents include solder and anaerobic. After insertion of the male member into the female body, the bonding agent bonds the outer surface of the male member to the inner surface of the female body. The bonding agent thus fills any gaps developed between the female body and the male member. However, the bonding agent must be applied just prior to insertion of the male member into the female body. Should the bonding agent be applied in advance, contaminants will adhere to the outer surface of the bonding agent. This lack of ability to apply the bonding agent in advance increases complexity and labor for the final assembly manufacturer""s assembly plant.
Another disadvantage of this type of fitting is the need to install the ring onto the tube forming the male member just prior to the insertion of the male member into the female body. Since the ring is loosely and slidably mounted, the ring can slide off the end of the male member or up the tube away from the male member, thus preassembly of the ring onto the tube is not feasible. This lack of feasibility for preassembly of the ring increases complexity and labor for the final assembly manufacturer""s assembly plant.
The present invention is directed to a fitting assembly for fluid and vapor connection comprising a first tube, a second tube and a ring. The first tube has a male member at the end of the first tube and a radially enlarged upset formed at a distance from the end of the first tube. The second tube has a hollow female body formed at the end of the second tube. The male member is received in the female body. The ring surrounds the female body. The ring has an axial bore with an innermost diameter smaller than the outermost diameter of the female body for deforming the female body radially inward. The innermost diameter of the axial bore is smaller than at least a portion of the upset of the first tube.